1. Field
The invention relates generally to quantum computers. More specifically, the invention relates to generating fundamental logical operations in quantum computers.
2. Background
A classical computer operates by processing binary bits of information that change state according to the laws of classical physics. These information bits can be modified by using simple logic gates such as AND and OR gates. The binary bits are physically created by a high or a low energy level occurring at the output of the logic gate to represent either a logical one (e.g. high voltage) or a logical zero (e.g. low voltage). A classical algorithm, such as one that multiplies two integers, can be decomposed into a long string of these simple logic gates. A set of such gates is said to be complete if all possible algorithms can be generated from only that set of gates. For example, the classical NAND gate by itself forms a complete set.
Like a classical computer, a quantum computer also has bits and gates. But instead of using logical ones and zeroes, a quantum bit (“qubit”) uses quantum mechanics to occupy both possibilities simultaneously. This ability means that a quantum computer can solve a large class of problems with exponentially greater efficiency than that of a classical computer.
It is widely known that a combination of single-qubit operations with a two-qubit controlled-not (CNOT) gate forms a complete set for quantum computation. It has been demonstrated that some single qubit operations can be performed by coupling the qubit to a resonator. An objective of ongoing research in this field is to develop a more efficient means of achieving arbitrary qubit operations.